I got this issue too, but not until after the party so I blamed Halsin, particularly as talking to him after his initial chat the party was a bit buggy (I’ve not had a problem with Volo, though).

As far as I can tell it doesn’t mess up genuine dialogue scenes as I still got a yellow exclamation mark when someone did want to talk.

I reported my bug to Larian, so if yours is the same problem then hopefully they’re already aware and it’s on the list to fix.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"